<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" name="viewport" content="width=device-width, initial-scale=1"/> <link rel="stylesheet" type="text/css" href="css/bootstrap.css" /> </head> <body> <nav class="navbar navbar-default"> <div class="container-fluid"> </div> </nav> <div class="col-md-6 well"> <hr style="border-top:1px dotted #ccc;"/> <div class="col-md-6"> <br /> <div class="form-group"> <input type="number" class="form-control" id="height" required="required"/> </div> <div class="form-group"> <input type="number" class="form-control" id="width" required="required"/> </div> <br /> </div> </div> </body> </html>
function calculateArea(){ var height = document.getElementById('height').value; var width = document.getElementById('width').value; var area = (width * height) / 2; document.getElementById('height').setAttribute('readonly', 'readonly'); document.getElementById('width').setAttribute('readonly', 'readonly'); document.getElementById('result').innerHTML = "<center><label style='font-size:26px;'>The area of triangle is</label> <br /><span class='text-primary' style='font-size:30px;'>"+area+"</span></center>"; } function reset(){ document.getElementById('height').value = ""; document.getElementById('width').value = ""; document.getElementById('height').removeAttribute('readonly'); document.getElementById('width').removeAttribute('readonly'); document.getElementById('result').innerHTML = ""; }